The use of congeneric surveying poles for staking out and measuring terrain points or similar devices are known from prior art, for example from U.S. Pat. No. 7,788,815 B2, EP 1 130 355 A2 or JP 2000 234933 A. In survey applications using TPS or GNSS equipment, a position measurement is not taken of the target point directly, but rather of a reflector, a receiver or an antenna on the surveying pole. A conclusion to the position of the target point is possible due to the known spatial relationship between the reflector, the receiver or antenna, and the tip of the pole. With this method it is possible to circumvent obstacles which stand in the direct way between the measuring instrument and the target point.
To provide further flexibility for such obstacles avoidance, usual practice is the realization of a pole adjustable in its height. Said surveying pole is typically used together with a geodetic device comprising a measuring light sender and a measuring light receiver. For example, the measuring light source (such as a rotating laser device) can emit a plane of light that defines a reference plane at a known elevation, wherein the reference plane may be level or sloping. When light of the plane incide into a reflector coupled to the surveying pole and configured to be moved up and down the pole, the light is sent back to and detected by the geodetic instrument. As the geodetic instrument and the surveying pole are wirelessly connected with each other in order to communicate, the pole can be given an indication by the geodetic instrument, when visual contact has been obtained. From that, the pole can give notice to its user by an audible, vibratory and/or visual signal.
Survey pole solutions comprising a GNSS antenna are not reliant on a terrestrial geodetic instrument as they obtain their positional data via a satellite positioning system. However, to increase measurement accuracy, a GNSS reference station might be provided at the scene. In traditional surveying with a GNSS-pole the surveyor places the pole tip onto the measuring point, levels the pole and triggers the GNSS measurement, the results of which include also height information.
As for the height measurement of the pole adjusted in the described way, current solutions are either manual reading from a tape measure or automatic measurements with a measurement system based on the surveying pole. Conventional, i.e. analogue, surveying poles typically have visual measurement markers (such as a scale and numbers) printed on the pole or on a tape attached to the pole, which makes them operate like an ordinary measuring tape. For this purpose, the poles have a telescopic structure which provides the height adjustability and the measurability by shifting the scale according to the height adjustment.
Other solutions, such as offered in U.S. Pat. No. 7,373,725, provide automatic height measurement using electronic appliances, wherein a reference indicator and a grade-rod reference surface indicating absolute height marks are used for the height detection. Differences in electromagnetic coupling are detected with help of the incremental inductive path detection. Derived from this are a relative movement and a height measurement resorting to this relative distance travelled
Height measuring solutions for surveying poles known from prior art have several common disadvantages. As surveying jobs are subject to a high expenditure of time, known surveying poles do not meet the needed time efficiency requirements, as a high share of manual steps is necessary. Also due to manual steps, common surveying poles allow for too many sources of error caused by the user.